The present invention generally relates to a method for driver assistance for a vehicle. The invention also relates to a corresponding driver assistance system and a computer program product.
Recent advances in assisting a driver operating a vehicle have successfully emerged into the market as they compensate shortcomings of human drivers, such as inevitable reaction times for emergency brakes or deficiencies for vehicle stabilization.
Systems providing such a drive assistance may typically be installed with the vehicle and comprise a suitable sensor arrangement (e.g. including radar, lidar, image processing) or the evaluation of vehicle-to-vehicle communication for detecting the vehicle environment and determine possible collision objects. Such a system may additionally be connected to the break arrangement of the vehicle and thus be capable of completely preventing an imminent collision or at least minimizing the consequences of a collision by an autonomously initiated full brake application.
Typical implementations of the above discussed functionality may for example find its way into automatic cruise control systems (ACC system), where the ACC system allows adaptability in regards to a preceding second vehicle such that the vehicle-to-vehicle distance is kept long enough to minimize a collision. In some instances, the ACC system may also take into account a further (e.g. third) vehicle placing itself in between the own vehicle and the second vehicle, possibly making it necessary to (emergency) break the own vehicle.
Even though the above discussed implementations for driver assistance minimizes the risk for the own vehicle being part of a collision, vehicles in general are poorly equipped to automatically handle these instances. Accordingly, it would be desirable to introduce a holistic approach where the overall traffic situation is taken into account for reduce the overall risk of collisions, also for vehicles not explicitly equipped with systems for driver assistance.
According to an aspect of the invention, the above is at least partly alleviated by a method for driver assistance for a first vehicle, the method comprising the steps of monitoring, using a detection arrangement provided with the first vehicle, a predefined area surrounding the first vehicle, identifying a road condition ahead of the first vehicle and within the predefined area, the road condition fulfilling a predetermined risk criteria, identifying a second vehicle initiating a maneuver for overtaking the first vehicle, and determining a collision risk level for the first and/or second vehicle during the overtaking maneuver.
In accordance to the invention, the surroundings of the first vehicle is typically automatically monitored, for identifying one or a plurality of risky road conditions ahead of the first vehicle as well as for identifying surrounding vehicles. By means of the invention, if it is identified that a surrounding vehicle (i.e. a second vehicle) is in the process of initiating an overtaking maneuver, such an initiated condition will be taken into account and correlated with the one or plurality of identified risky road conditions. The correlation between these two parameters, i.e. the risky road condition(s) and the just initiated overtaking maneuver by the second vehicle will be used to determine collision risk level for the first and/or second vehicle at the time during which the second vehicle in fact is performing the overtaking maneuver.
Accordingly, the act of the second vehicle in initiating the overtaking maneuver will spark a risk assessment of the overall traffic situation, resulting in the determination of a current risk level for the vehicles involved, i.e. the first and the second vehicle (and possibly further surrounding vehicles). The determined collision risk level may consequently be used for warning the first and/or the second vehicle of the risky situation, or alternatively for requesting the first and/or the second vehicle to modify its driving behavior. In both these cases, the general purpose is to use the detection arrangement provided with the first vehicle to influence the operation of at least one of the first vehicle (e.g. being the first/own vehicle) and the second vehicle (i.e. a surrounding vehicle coming from behind of the first vehicle, travelling in the same direction as the first vehicle and in the process of initiating the overtaking maneuver) such that the overall risk of collisions is reduced and the overall traffic situation is improved. The intention of the invention is accordingly to improve the overall traffic situation not only for the own vehicle but also for vehicles in the surrounding of the own vehicle.
The warning to the second vehicle may for example be provided as a visual, acoustic or haptic warning signal, whereas the modification of the driving behavior may include adjusting at least one of a speed and/or a lateral position of the first and/or the second vehicle.
Communication between the first and the second vehicle for providing instructions and/or warnings may be in any form, typically based on radio or optical communication (e.g. vehicle-to-vehicle communication). In case of requesting a modified driving behavior of the first and the second vehicle, such a request may for example be communicated to a control arrangement for operating the first and/or the second vehicle, for example for the purpose of activating the break arrangement of the first and/or the second vehicle.
In an embodiment of the invention, the step of identifying the road condition ahead of the first vehicle comprises the step of identifying an obstacle ahead of the first vehicle. Such an obstacle may for example be a fixed obstacle, such as a road condition where the road traveled by the first and second vehicle is adjusted from two to one lane (2-to-1 roads). However, the obstacle may alternatively be “non-static”, for example being a further (third) vehicle travelling in another lane and in e.g. the opposite direction as compared to the first and the second vehicle. In a similar manner as above, the instructions/warning signal may also be provided to the further (third) vehicle.
Possibly, the third vehicle may also be a “slow” third vehicle travelling in the same direction but in a different lane as compared to the first and the second vehicle, such as for example in case of a traffic congestion being the reason of the third vehicle slowing down. As such, the above mentioned predetermined risk criteria may for example include comparing an identified type of obstacle with a list of situations where an increased risk has been predetermined. Accordingly, in such an embodiment it may additionally be desirable to determine a distance and relative speed between the first vehicle and the obstacle, determine a distance and relative speed between a second vehicle and the obstacle, and calculate, based on the determined distances and speeds of the first and second vehicles in relation to the obstacle, the collision risk level for the first and/or the second vehicle.
In another embodiment of the invention, the step of monitoring the predefined area surrounding the first vehicle may comprise the step of determining road geometry data for a predetermined area surrounding the first vehicle. Such information may for example be used in relation to identifying road conditions fulfilling the predetermined criteria. That is, the identified road condition may not necessarily only include fixed or “non-static” obstacle, but may also include conditions such as listed road work, hills/crests, curves/corners, etc.
The road geometry data may in an embodiment be taken into account for calculating a possible travel trajectory for the second vehicle based on at least one of a position and speed of the second vehicle, and correlating the road geometry data and the possible travel trajectories for the second vehicle for determining if the possible travel trajectory has a collision risk level being above a predetermined threshold. The determination of the possible travel trajectory for the second vehicle will be further discussed below in relation to the detailed description of the invention.
According to another aspect of the present invention there is provided a driver assistance system for a first vehicle, the driver assistance system comprising a detection arrangement provided with the first vehicle and configured for monitoring a predefined area surrounding the first vehicle, and a control unit connected to the detection arrangement and adapted to receive a detection signal from the detection arrangement, the control unit configured to identify a road condition ahead of the first vehicle and within the predefined area, the road condition fulfilling a predetermined risk criteria, detect a second vehicle travelling in the same direction as the first vehicle, wherein the control unit is further configured to identify, based on the detected second vehicle travelling in the same direction as the first vehicle, a maneuver initiated by the second vehicle for overtaking the first vehicle; and determine a collision risk level for the first and/or second vehicle during the overtaking maneuver. This aspect of the invention provides similar advantages as discussed above in relation to the previous aspect of the invention.
According to a still further aspect of the present invention there is provided a computer program product comprising a computer readable medium having stored thereon computer program means for controlling a driver assistance system for a first vehicle, the driver assistance system comprising a detection arrangement provided with the first vehicle and configured for monitoring a predefined area surrounding the first vehicle, and a control unit, wherein the computer program product comprises code for monitoring a predefined area surrounding the first vehicle, code for identifying a road condition ahead of the first vehicle and within the predefined area, the road condition fulfilling a predetermined risk criteria, code for identifying a second vehicle initiating a maneuver for overtaking the first vehicle; and code for determining a collision risk level for the first and/or second vehicle during the overtaking maneuver. Also this aspect of the invention provides similar advantages as discussed above in relation to the previous aspects of the invention.
The computer readable medium may be any type of memory device, including one of a removable nonvolatile random access memory, a hard disk drive, a floppy disk, a CD-ROM, a DVD-ROM, a USB memory, an SD memory card, or a similar computer readable medium known in the art.
Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled addressee realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.